From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Serge E. Hallyn" <serge.hallyn@canonical.com>
Subject: Re: [PATCH] user_ns: Improve the user_ns on-the-slab packaging
Date: Tue, 7 Dec 2010 08:27:47 -0600
Message-ID: <20101207142747.GB4674@hallyn.com>
References: <4CFE40D1.5000309@parallels.com>
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To: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Linux Containers <containers@lists.osdl.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Quoting Pavel Emelyanov (xemul@parallels.com):
> Currently on 64-bit arch the user_namespace is 2096 and when
> being kmalloc-ed it resides on a 4k slab wasting 2003 bytes.
> 
> If we allocate a separate cache for it and reduce the hash size
> from 128 to 64 chains the packaging becomes *much* better - the

Hey Pavel,

I trust you've done some performance tests and found no
regressions with a few hundred users?

-serge